Standardise ratio names

[christianhg]

It would be awesome if names, casings and even the order of the ratios would match across these two modules.

Ratios copied from the JavaScript module:

var minorSecond   = 16/15;
var majorSecond   = 1.125;
var minorThird    = 1.2;
var majorThird    = 1.25;
var perfectFourth = 4/3;
var augFourth     = 1.414;
var perfectFifth  = 1.5;
var minorSixth    = 1.6;
var goldenSection = 1.61803398875;
var majorSixth    = 5/3;
var minorSeventh  = 16/9;
var majorSeventh  = 1.875;
var octave        = 2;
var majorTenth    = 2.5;
var majorEleventh = 8/3;
var majorTwelfth  = 3;
var doubleOctave  = 4;

Ratios copied from the Sass module:

$double-octave    : 4                 ;
$pi               : 3.14159265359     ;
$major-twelfth    : 3                 ;
$major-eleventh   : 2.666666667       ;
$major-tenth      : 2.5               ;
$octave           : 2                 ;
$major-seventh    : 1.875             ;
$minor-seventh    : 1.777777778       ;
$major-sixth      : 1.666666667       ;
$phi              : 1.618034          ;
$golden           : $phi              ;
$minor-sixth      : 1.6               ;
$fifth            : 1.5               ;
$augmented-fourth : 1.41421           ;
$fourth           : 1.333333333       ;
$major-third      : 1.25              ;
$minor-third      : 1.2               ;
$major-second     : 1.125             ;
$minor-second     : 1.066666667       ;

[christianhg]

I've decided to publish som standardised proportions for both JavaScript and Sass. I hope, you'll want to use them in your projects: https://github.com/proportions/proportions